'218 
NERVOUS SYSTEM — PEDAL GANGLIA. 
bral centre, and conse(iuently the pleuro-pedal connectives are still 
distinct from the cerebro-pedal connectives, with which, in most 
si)ecies, they are intimately fused to form the compound cerebro- 
pleuro-pedal connective. 
The Pedal ganglia, also called the antero-inferior or suboesophageal 
ganglia, are placed beneath the msophagus and within or near the foot 
and are more especially 
motor ; they are earlier 
in development and 
more constant in their 
character than the 
viscei'al centres, and 
innervate the foot and 
its dependencies, being 
correlated in size with 
its development ; they 
are joined with the 
cerebral and visceral 
Fig. 431. — Pedal ganglion cells, with their nerve prolonga- ^ .1* 1 * 1 
tions, from L/nio pictoru/n X oOO (after Rawitz). Uy pclllPtl COU- 
nectives and are usually in intimate association with the otocysts. 
In many Streptoneures the pedal ganglia still I'etain the archaic 
character of long ganglionic nerve cords, traversing the foot longi- 
tudinally and united at intervals 
by numerous slender commissural 
fibrils, in addition to the chief pedal 
commissure at the anterior end of 
the foot, near the junction of the 
cerebral and visceral connectives. 
Tbe regular repetition of these 
slender commissures recalls the 
ladder-like ai’rangement of the 
pedal nerves in the Isopleura. The 
male organ of repr(jduction is of 
l)edal nature and usually innervated 
by the pedal ganglia. 
In the Euthyneura the pedal 
ganglia have generally become intimately fused and approximated to 
the ventral side of the oesophagus, and usually bear the otocysts 
adherent to or actually imbedded in their umler surface. 
F'ig. 432.~Sole of yivipara vivipara (L.) 
to show the pedal nerve cords, which represent 
the pedal ganglia and also showing the central 
pedal blood sinus, X 3 (after Siniroth). 
